1½ oz reposado tequila1 oz amontillado sherry¾ oz lime juice½ oz demerara syrup (2:1)¼ oz ginger juice½ oz Fernet Branca3 dash Angostura bitters2 kaffir lime leaf
instructions :

Muddle the makrut lime leaves (if using) with the demerara syrup in a Collins glass.
Add the remaining ingredients to the glass and fill three-quarters full with crushed ice.
Use a swizzle stick or tsp to swizzle the mixture until cold.
Pack the glass with ice to form a rounded mound on top, and dash Angostura bitters over the ice.

source :